RESUMO
Azole-containing selenoethers, 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-selena pentane and 1,3-bis(1,2,3-benzotriazol-1-yl)-2-selena propane were prepared by the reaction of corresponding tosylate or chloride with sodium selenide generated in situ from elemental selenium and sodium formaldehydesulfoxylate (rongalite).
Assuntos
Química Orgânica/métodos , Éter/síntese química , Pirazóis/química , Triazóis/química , Cristalografia por Raios X , Éter/química , Conformação Molecular , Selênio/químicaRESUMO
The total synthesis of certain natural phenolglycosides of the family Salicaceae, namely: salireposide, populosides A, B, and C and not occurring in plants desoxysalireposide (2-(ß-D-glucopyranosyloxy)-benzylbenzoate) and per-acetate of iso-salireposide (2-(ß-D-glucopyranosyloxy)-5-benzoyloxy benzyl alcohol), starting from readily available phenols and glucose was accomplished. A simple method for the synthesis of phenolglycosides derivatives of 2-acyloxy salicyl and gentisyl alcohol was developed. The key step of these natural products' synthesis is a selective removal of acetyl groups in the presence of other acyl groups.
Assuntos
Produtos Biológicos/química , Produtos Biológicos/síntese química , Glicosídeos/química , Glicosídeos/síntese química , Salicaceae/química , Álcoois Benzílicos/química , Técnicas de Química Sintética , Glucosídeos/química , Hidroquinonas/químicaRESUMO
Several new bitopic pyrazole-containing ligands were prepared from the corresponding pyrazoles and tetrahalogen or tetratosyloxy derivatives of o-xylene and neopentane in a superbasic medium (KOH-DMSO).
Assuntos
Metais/química , Oxigênio/química , Pentanos/química , Pirazóis/química , Xilenos/química , Sítios de Ligação , LigantesRESUMO
Pyrazole and benzotriazole-containing thioethers, namely 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-thiapentane, 1,8-bis(3,5-dimethylpyrazol-1-yl)-3,6-dithiaoctane and 1,3-bis(1,2,3-benzotriazol-1-yl)-2-thiapropane were prepared and fully characterized. Oxidation of the pyrazole-containing thioether by hydrogen peroxide proceeds selectively to provide a sulfoxide or sulfone, depending on the amount of oxidant used. Oxidation of the benzotriazole derivative by hydrogen peroxide is not selective, and sulfoxide and sulfone form concurrently. Selenium dioxide-catalyzed oxidation of benzotriazole thioether by H(2)O(2), however, proceeds selectively and yields sulfoxide only.
